Source: Spinler SA, De Denus
S. Acute Coronary Syndromes. In: DiPiro JT, Talbert RL, Yee GC,
Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy:
A Pathophysiologic Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=7972196.
Accessed June 30, 2012.
- Acute coronary syndromes (ACS) includes all clinical syndromes
of acute myocardial ischemia resulting from an imbalance between
myocardial oxygen demand and supply.
- Diminished myocardial blood flow secondary to occlusive
or partially occlusive coronary artery thrombus
- Partially or completely occlusive clot forms on top of
ruptured atherosclerotic plaque within coronary artery.
- Release of adenosine diphosphate and thromboxane A2 from
platelets produces vasoconstriction and platelet activation.
- Activation of extrinsic coagulation cascade leads to formation
of fibrin clot.
- Ventricular remodeling after myocardial infarction (MI) may
lead to heart failure (HF).
- >1.2 million Americans experience ACS each year; 220,000
die of MI.
- Up to 6.3 million emergency department visits each year are
linked to possible ACS.
- >17.6 million in U.S. have coronary heart disease (CHD).
- Risk factor modification (smoking cessation; control of
blood pressure, diabetes, dyslipidemia)
- Symptoms: Chest discomfort (usually at rest), severe new-onset
or increasing angina. Discomfort may radiate to shoulder, down left
arm, or to back or jaw. Nausea, vomiting, diaphoresis, and shortness
of breath may also occur.
- Signs: Patients with ACS may present with signs of acute HF
Means of Confirmation
- Use patient symptoms, past medical history, ECG, and troponin
or CK-MB to stratify patients into low, medium, or high risk.
- Increased troponin I or T with a typical rise and fall
- Increased CK-MB may be used if troponin test is not available.
- Serum potassium and magnesium, glucose, serum creatinine,
complete blood cell count (CBC), coagulation tests, and fasting
- 12-lead ECG findings indicating myocardial ischemia or
MI include ST-segment elevation, ST-segment depression, and T-wave
- Classification of ACS
- ST-segment elevation
(STE) ACS or STE MI
- Non–ST-segment elevation (NSTE) ACS, which includes
non–ST-segment elevation myocardial infarction (NSTE MI)
and unstable angina (UA)
- Early restoration of blood flow to the infarct-related
- Prevention of complications and death
- Prevention of coronary artery reocclusion
- Relief of ischemic chest discomfort
- Resolution of ST-segment and T-wave changes on ECG
- Hospital admission, oxygen if saturation <90%,
continuous ST-segment monitoring, glycemic control, frequent vital
sign measurement, bedrest, stool softeners, and pain relief
- For patients with STE MI, attempt to reestablish coronary
perfusion immediately (without evaluation of biochemical markers).
- Obtain serial biochemical markers in patients with NSTE ACS
who are low risk.
- High-risk NSTE ACS patients should undergo early coronary
angiography (within 12–24 hours) and revascularization
if significant stenosis is ...